Soft condensed matter commonly deals with materials that are mechanically soft and, more importantly, particularly prone to thermal fluctuation effects. Charged soft matter systems can be manufactured artificially as polyelectrolytes to serve as superabsorbers in dypers, as flocculation and retention agents, as thickeners and gelling agents, and as oil-recovery process aids. They are also abundant in living organisms, mostly performing important structural (e.g. membranes) and functional (e.g. DNA) tasks. This book describes the many areas in soft matter and biophysics where electrostatic interactions play an important role. It offers coverage of recent theoretical approaches, advances in computer simulation and experimental techniques.